It is an object of the present invention to provide a gas driven engine having a double acting piston in a chamber that is driven in a reciprocating motion with a drive train from the piston to the power output drive shaft wherein the drive train is carried inside the piston and through the chamber wall to the power output drive shaft, at a part of the chamber wall that is covered throughout the engine cycle of operation.
It is a further object that the drive train exposure to the driving gas be minimized.
It is another object to provide a double acting or two cycle gas driven engine with a piston in a chamber engaging and output drive shaft through a side wall of the chamber, perpendicular to the piston motion using an eccentric gear train that converts the reciprocating motion of the piston to rotational motion of the output power drive shaft.
Another object of the invention is to provide a reciprocating piston mechanism that does not require the conventional crankshaft arrangement of piston and piston rod connected to the crankshaft.
According to features of the present invention, a piston mechanism for gas driven engines, fluid motors, pumps and the like is adapted with a double eccentric drive from the piston to the output drive shaft that is contained inside the piston and through a part of the piston chamber wall that is covered throughout the engine cycle of operation, so that the drive is not exposed to the piston driving gases. In preferred embodiments, the double eccentric drive has a minor eccentric engaged by the minor internal gear that is fixed to the inside of the piston, which converts the piston reciprocating drive motion to an orbiting axle of the minor eccentric and a major eccentric that engages an the major internal gear that is fixed to the outside of the chamber and carries the output drive shaft, and the eccentrics are connected at their orbiting axles so that the major eccentric converts the orbiting motion of the minor eccentric axle to a rotational motion of the output drive shaft. In particular embodiments, orbiting axle of the minor eccentric and an orbital axle of the major eccentric are connected by gears that engage the minor internal and the major internal gears and these gears are referred to herein as the minor and major pinion gears, respectively.
Specific examples incorporating features of the invention provide a housing that contains the chamber, piston, double eccentric drive and output drive shaft, the output drive shaft and major eccentric internal gear are concentric and are carried by said housing, the output drive shaft being rotatable therein, the minor eccentric internal gear is carried by said piston and the major and minor pinion gears are fixed to the orbiting axles of the minor and major eccentrics, respectively.
In an engine according to the present invention having input and output (exhaust) gas flow ports, the piston periodically covers and uncovers openings (the ports) in the chamber. In operation, when the compressed gasoline-air mixture over the piston is ignited, the piston thrusts downward and in so going uncovers the exhaust port. The burned gasses (exhaust) in the cylinder which are still under high pressure can then escape through the exhaust port. When the piston descends further, its upper edge uncovers the inlet port which admits fresh gas-air mixture into the cylinder so that the remaining burned gasses (exhaust) are flushed out. When the piston rises again (second stroke), all of the ports are covered for a time and during this period, the gas-air mixture is compressed, so that a new cycle can begin.
Among the objects of the present invention are also the following: to provide a double acting four cycle internal combustion engine that provides the four stroke cycle at both ends of the piston; to provide the forced lubrication by means of the minor eccentric and piston vanes located within to cause a pumping action of the lubricant; to provide a reciprocating piston mechanism for fluid motors and pumps having a single or double acting capability and; to provide two or more chambers arranged in suitable manner so as to achieve multiple strokes.
A further object is to provide a two cycle internal combustion engine that eliminates the need for the conventional crankcase scavenged air and the lube oil entrainment and emission problems associated therewith.
A further object is to provide a two cycle internal combustion engine that utilizes a rotary valve for air admission to both compression and combustion ends of the chamber, reducing the problem of xe2x80x98blowbackxe2x80x99 that occurs with conventional xe2x80x98portedxe2x80x99 two cycle engines. However this does not preclude the use of porting only where less expensive smaller engines must be used.
A further object is to provide a two cycle engine that is double acting having power strokes at both ends of the piston and in which the engine is aspirated by other means, or is self aspirating, thus providing two power strokes per revolution of the drive shaft.
A further object is to provide a double acting four cycle internal combustion engine that provides the four stroke cycle at both ends of the piston.
A further object is to provide the forced lubrication by means of the minor eccentric and piston vanes located within to cause a pumping action of the lubricant.
A further object is to provide a reciprocating piston mechanism for fluid motors and pumps having a single or double acting capability.
A further object is to provide two or more chambers arranged in suitable manner so as to achieve multiple strokes.
According to embodiments of the present invention, a piston mechanism for internal combustion engines, fluid motors pumps and the like, has a double eccentric drive including a major and minor eccentric, perpendicular to the piston motion that is caused to rotate by means of a gear train and connected in such a manner to the piston as to impart a reciprocating action to the piston in the chamber. Each eccentric drive includes an internal gear and a pinion gear. The gear ratios of the internal gear to the pinion gear in both the major and minor eccentrics is 2:1 and the position and attitude of the piston is positively controlled by the gears and is independent of the forces between the piston and the chamber wall.